Anything else?

• Constructor delegation: new() calls init()
• In our case:

$self->init( { colour  => 'pink'... } );

• So we need to provide init() if we want to handle params when constructing

sub init {
    my ($self, $params) = @_;
    ...
    return $self; # must return self...
}

• As the matter of fact, new() returns init(@params)